Beginner here, I want to do something like this
If you are a beginner, my recommendation is to watch the full Donut beginner tutorial series of channel Blender Guru on youtube.In that donut tutorial series, you will learn modeling, some sculpting tools, some modifiers, particles and about materials and texture painting. Then try to study all the  sculpting tools so that it will help you to make landscapes. you can fins tutorial series about sculpting in youtube. then try modifiers tools too. So first try that donut tutorial esries.